Steam trap with a float-operated slide valve

ABSTRACT

A steam trap employs a rotatable and slidable valve to open and close the outlet of a condensate chamber and to vent the outlet at low temperature. The valve is connected to a float which controls opening and closing of the outlet by rotating the valve, the connection between the float and the valve being made by a pair of arms at least one of which is bimetallic so as to respond to temperature differences and laterally shift the valve to control the venting.

United States [72] Inventor Hans Richter 1,571,921 2/1926 Hutchinson 236/53 1 28 Bremen, Reinthalerstrassemfi, Bremen, 2,825,508 3/1958 Velan et a1 236/53 Gem"! FOREIGN PATENTS Q S' 3 33 1,025,896 3/1958 Germany 236/53 [45] Patented A 1971 1,099,550 2/1961 Germany 236/59 1,162,851 2/1964 Germany 137/194 Primary Examiner-Meyer Perlin [54] STEAM TRAP WITH A MAT-OPERATED SLIDE Assistant E i r W C. Anderson VALVE AttarneyWaters, Roditi, Schwartz & Nissen 14 Claims, 12 Drawing Figs.

[52] US. Cl 236/59, 137/94, l37/625.4l, 137/6344 [51] hit. Cl Fl6t 1/03 ABSTRACT: A Steam trap employs a rotatable and Slidable [50] Field 01 Search 62/471, valve to open and close h outlet of a condensate chamber 473; 236/52 60; 137/192 and to vent the outlet at low temperature. The valve is con- 6254] nected to a float which controls opening and closing of the outlet by rotating the valve, the connection between the float [56] Referenm CM and the valve being made by a pair of arms at least one of UNITED STATES PATENTS which is bimetallic so as to respond to temperature differences 1,308,856 7/1919 Morgan 236/59 X and laterally shift the valve to control the venting.

' 6 1 /0 9 l4 F' 1 b r 6 1/? 6a.

PATENTEU AUB24|97| 3501; 309

sum 1 or 5 FIG./

PATENTED AUG24 l97l SHEET 3 [IF 5 This inventionrelates to a float-controlled trap fitted with a swivel valve housed in a seat and regulated by means of a ball float mounted on a flat lever, and with a thermally controlled vent hole through which the interior of the casing of the trap, when its temperature is below a predetermined value communicates with a condensation outlet orifice.

In a float-controlled steam trap of this type, evacuation of the air and gases contained in the steam frequently raises difficulties. These can wholly preclude the inflow of thecondensate into the trap chamber and thus nullify the operation of the trap in steam installations. Devices are known which serve to discharge the air and gases either through jets or supplementary vent valves. I

An object of this invention is to simplify the ventilation system.

This object is achieved by making the arms of the float lever of bimetallic material in which the more strongly expanding layer is toward the outside and its two extremities are fixed to the seat and/or the slide valve in such a way that the spread which occurs upon cooling causes a transverse deflection of the swivel valve in the direction of its length, whereby a notch in the top of the swivel valve connects a vent hole in the seat with the outlet.

The expansion of the two extremities of the float lever arm, which occurs transversely to the lever guide motion produced by the float, is utilized for the purpose of shifting the swivel valve transversely. This transverse displacement causes the swivel slide in its cold state, when the most air is available, to connect a drilled vent with the discharge outlet so that the air can escape. The lever can be of U-shape and the opening and closing forces which bring about the rotation of the valve operate on the upright section of the U-shaped lever; the forces causing displacement in the longitudinal direction act on the flat section and thus do not interfere with one another. The swivel valve is advantageously placed high in the casing and the valve is connected to the lower condensate chamber by means of a depending pipe. In such a case, the construction according to the invention makes it possible to provide a particularly high vent hole in the casing.

. According to a modified version of this invention, the lever is formed with two arms shaped to the curvature of the spherical float and have ends secured to the float adjacent the middle portion thereof, which in most cases is reinforced. The adaptation of the arms to the shape of the float causes the arms to contact the surface of the float when the chamber temperature exceeds 100' C. and thereby they are restricted from further thermal distortion when the temperatures continue to rise. On cooling, the arms are lifted from the surface of the ball float and are able to complete its travel freely. This is achieved preferably by making the radius of curvature of the arm specifically equal to the radius of the ball float, with the connection of the ends of the arms slightly offset from the center of the float.

Each of the aforementioned curved portions is connected to a portion of reverse curvature and the latter portions of the arms are connected to free end portions which engage the ends of the valve. Moreover, according to the invention, the curved portions of each arm can have the bimetallic character reversed, i.e., with the higher expansion layer on the outer face for the portion facing the float and on the inner face of the other portion for the purpose of preventing or restricting the skewing of the shank ends which may come about from severe displacement strain. Otherwise, the skewing of the free ends of the arms is compensated, according to the invention, by providing one arm with a slot at its free end running lengthwise and receiving a flat end portion on the end of the valve. The area of contact, where the flat end portion merges with the cylindrical portion of the valve, is curved and on the opposite side of the arm a vertical cylindrical pin is secured to the flat end portion, thus forming a hinge joint that allows the free end of the arm to pivot without disturbing the valve in an axial direction. The valve is connected at its opposite end with the other arm in such a way as to prevent contact of the first arm with the side of the valve seat which could prevent free movement of the arm.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevation view, partly in cross section, of a steam trap according to the invention;

FIG. 2 is a plan view of a portion of the trap under conditions of low temperature therein;

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view similar to FIG. 3, under conditions of high temperature;

FIG. 5 is an elevational view, partly in cross section, of a modified version of the steam trap;

FIG. 6 is a plan view of a portion of the trap of FIG. 5;

FIG. 7 is a plan view similar to FIG. 6, under conditions of high temperature;

FIG. 8 is a cross section, on an enlarged scale, taken along lines 8--8 in FIG. 4;

FIG. 9 is a cross section taken along broken lines 9-9 in FIG. 8;

FIG. 10 is a view similar to FIG. 8, showing the device in another condition of operation;

FIG. 11 is a cross section taken along broken line 11-11 in FIG. 10; and

FIG. 12 is a cross section taken along line 12-12 in FIG. 10.

DETAILED DESCRIPTION A condensation product flows through a feed or inlet pipe 1 into a trap chamber 2, which in this form of construction is detachable from below, while a cap 3 carrying the feed pipe 1 and an outlet pipe 16 can remain in the pipe line.

A float 4 of spherical form is arranged in trap chamber 2. The position of float 4 is determined by the level of condensate in the chamber, as shown in FIG. 1. The position of float 4, which varies in accordance with the condensate level, acts through a U-shaped lever 5 to govern operation of a swivel valve 6. In this respect the valve is rotatable in a seat body 11, which is mounted in the cap 3. The lever 5 is fixed to float 4 at weld 7 and rotates the valve 6 in accordance with change in the level of condensate in chamber 2. The body 11 has an outlet bore 15 which opens into pipe 16, and the valve 6 has a recess 21 which, when the float is raised, provides communication between the bore 15 and the condensate in the chamber via a depending pipe 17 which extends close to the bottom of chamber 2 so as to be immersed in condensate. When the float is lowered, as shown in FIG. 1, the recess 21 is disconnected from bore 15 and the path to pipe 16 is thereby closed. Hence, the float controls the level of condensation in chamber 2. An ascending vent hole 13 communicates in a manner to be described, with the outlet bore 15 when the interior of the trap chamber 2 is cold. Because of the high location of the swivel slide valve, vent hole 13 opens into the upper part of the trap chamber, actually into the inside space of cap 3. It can then lead into a side of the cap turned away from the flow, where it is well protected from clogging, which feature is insured by its high location.

FIG. 2 shows the construction of the two arms 5a and 5b of the float lever 5. The arms are bimetallic (preferably two different steel materials with different expansion coefficients), and the more expansible material is located on the outside. FIG. 2 shows the position of the arms when the inside of the trap chamber is cold.

The arms 5a and 5b have two free ends 8 and 9 which encircle ends 611, 6b of swivel slide 6. The end 60 is of smaller diameter than the main body of swivel valve 6 and end 611 is fitted with slight clearance into a drilled circular hole in end 8 of arm 5a. The other end 6b of swivel valve 6 has one or more flat edges and end 9 of arm b has a corresponding shaped opening which engages around end 6b and thus transmits the pivotal movement of float 4 as a rotation to swivel valve 6.

The expansion of the ends of lever 5 occurring upon change in temperature is transmitted at end 9 to swivel valve 6 as a displacement thereof, while end 8 is constrained laterally in a slot 10 in seat body 11. The transmission of the motion of end 9 takes place in one direction (to the right in FIG. 3) via the engagement of end 9 with a shoulder 20 on the swivel valve resulting from the presence of the one or more flat edges on end 6b. The valve 6 is moved in the other direction (to the left in FIG. 4) by the engagement of end 9 with a cotter pin or a spring washer 19 snapped into a groove in end 6b. The clearance between the shoulders 14,20 on the two ends of swivel valve 6 is so adjusted that the ends of lever 5 are tight against the shoulders at a temperature of 100 C. and further increases of temperature can no longer operate the lever, this being the arrangement shown in FIG. 4.

FIG. 2 shows the milled recess 12 in the swivel valve 6 in a position which provides communication between vent hole 13 and outlet bore 15. This position is obtained by transverse displacement of the swivel valve as a result of the spread of the ends of float lever 5 when the lever is cold. The air (and subsequently the condensate) passes through bore 15 to the outlet pipe 16.

Referring next to FIGS. 5-12, therein is shown a modified version of the trap and prime reference numerals will be used for structure which is similar to that in the embodiment of FIGS. l-4.

In FIG. 6 it is seen that the construction of the lever 5 connected to the float 4' and its engagement with the swivel valve 6' is modified with respect to the construction in FIG. 2.

In FIG. 6 the ends 7a and 7b of the arms 5a and 5b are secured to the float 4' proximate a central reinforcement bead 41: thereof and the opposite free ends 51, 5a of the arms engage valve 6' in such a manner as to produce rotation thereof when the level ofthe condensate changes in the chamber 2.

The arms have curved portions extending from ends 7a, 7b which have a radius ofcurvature r. approximately equal to the radius r of the float 4'. In the cold condition of the trap chamber, as shown in FIG. 6, these curved portions of arms 5a, 5b are spaced from the surface of float 4', as shown in FIG. 6. The ends 50 and 5d of the arms are then spaced apart a maximum distance as measured longitudinally along the valve 6'. The end 5c ofarm 5a, is held axially by a stop lever 10', as will be explained more fully hereafter, and the arm 5b is free to move the slide valve 6 laterally, as will also be explained more fully hereafter.

FIG. 7 shows the position of arms 5a and 5b when the interior of the trap chamber 2 is at steam heat, i.e. at temperatures exceeding 100 C. The curved portion of the arms have now contracted onto the surface of the float and cannot move further inward. Additionally, as shown in FIG. 8, the free end 5d has shifted inwards (and carried valve 6 to the right) and a shoulder 14', formed at a step in valve 6', abuts a bush 18 mounted between stop lever 10 and a flat surface of seat body 11. The end 5c of arm 5'11, is threadably mounted on bush 8. The end 5d of arm 5b is held in abutment against curved shoulders by a pin 19'. The distance between the shoulders l4 and 20' is greater than the distance between the opposite flat surfaces of body 11' and hence the end 50 of arm Sais prevented from coming into contact with the body 11 while further contraction of the ends of the arms is also prevented.

FIG. 10 is a cross section through seat body 11 showing how the free end 5d, when in the cold position (temperatures below l00 C.) has displaced the swivel slide 6' to the left, i.e. outwards, a sufficient distance, so that notch or channel 12, preferably in the form of a simple milled recess (FIGs9) connects the bore 15 in body 11 with vent outlet 13.

The slide valve 6' is formed with a flat end portion 617 which, as seen in FIG. 12, extends axially of arm 5b. The end 5d of arm 51: has a slot in which end portion 6b is received and the pin 19' is secured in portion 6b and engages the end 5d of arm 5b to hold the same against curved shoulders 20' so as to permit pivotal movement of arm 5b with respect to valve 6.

FIG. 12 is a view looking toward seat body 11', the longitudinal position of portion 6b along the longitudinal axis of arm 5b being visible. FIG. 12 also shows the recess 21 in valve 6 in the closed position for outlet 15, it being understood that in the opened position (float 4 in top positionnot shown) the outlet 15 is connected with pipe 17' and thereby with the condensate in the chamber. If, in the closed position shown in FIG. 12, the interior of the trap chamber is cold, i.e. below C., a connection is produced between outlet 15' and vent hole 13' through the recess 12' on swivel slide 6'. This connection, however, is interrupted as shown in FIG. 8 ifthe interior of the trap chamber 2' rises to temperatures exceeding IOO C. The action of the valve with respect to the regular removal of condensate is not prejudicially affected by the action of the valve in providing communication between the outlet15' and vent hole 13' when the chamber is cold.

What is claimed is:

1. A steam trap comprising a housing having an inlet and an outlet and a trap chamber for condensate, a slidable and rotatable slide valve supported in said housing to control opening of the outlet, a float in said chamber, lever means secured to said float and coupled to said slide valve for rotating the latter in accordance with the level of condensate in said chamber, to open and close said outlet, said lever means including two arms, at least one of which is bimetallic and un dergoes deformation, with temperature change, to slidably displace the slide valve, said slide valve having a notch and said housing having a vent outlet respectively positioned such that at low temperatures the notch in the slide valve provides communication between the vent outlet and the outlet of the housing, whereas at high temperature the slide valve is displaced and the vent outlet and housing outlet are discon nected.

2. A steam trap as claimed in claim 1, wherein said lever means comprises a U-shapcd lever inclusive ofsaid arms.

3. A steam trap as claimed in claim 2 comprising a seat body for said valve, the other of said arms having an end received in a slot provided in said body, said one arm having an end secured to said valve and freely movable laterally.

4. A steam trap as claimed in claim 3, wherein said valve has an end of reduced diameter engaged in a hole provided in said end which is received in the slot, the valve having an opposite end with at least one flat surface therein, the laterally freely movable end having an opening corresponding in shape to the end of the valve with the flat surface to encircle such end and provide a rotatable connection between said lever means and said valve.

5. A steam trap as claimed in claim 4, wherein said ends form shoulders on said valve, the distance between the shoulders being such that at temperatures of 100 C. the two ends of the arms are pressed against the shoulders.

6. A steam trap as claimed in claim 1, wherein said float has a spherical shape, said arms having first ends secured to said float adjacent the center thereof and second remote free ends extending parallel to one another and engaging the slide valve, said arms each including a first portion extending from said first ends and facing said float, said first portions of said arms being curved and having a curvature substantially corresponding to that ofsaid float, said arms each including a second portion connecting said free ends and said first portion, said second portion being curved and having a lesser curvature than said first curvature to smoothly blend therewith and with said free ends.

7; A steam trap as claimed in claim 6, wherein said first portion of each said arm has a radius of curvature substantially equal to the radius of said float, said first ends being slightly offset from the center of the float so that normally the first portion is spaced from the float, the first portion of the bimetallic arm having a more expansive la \'er on the outer surface thereof such that at a temperature of about 100 C. the

first portion of the latter arm is deformed and contacts the float along the surface thereof. 7

8. A steam trap as claimed in claim 7, wherein both arms are bimetallic.

9. A steam trap as claimed in claim 6, wherein said slide valve includes a flat end portion extending axially of said arms, said one arm having a longitudinal slot receiving said end portion, said slide valve having a convex shoulder in abutment with said first arm, and means secured to said slide valve to hold the first arm in abutment with said convex shoulder.

10. A steam trap as claimed in claim 9, wherein said shoulder is curved in a horizontal plane and said means for holding the first arm in abutment with the shoulder comprises a vertical pin in said pin engaging the first arm on the side thereof opposite the side in abutment with the convex shoulder.

11. A steam trap as claimed in claim 9 comprising a seat body for said slide valve, said seat body having opposite flat surfaces from which the ends of the valve protrude, said slide valve having a step at the end thereof remote from the flat end portion, said step forming a shoulder which is spaced from the convex shoulder a distance which is slightly greater than the distance between the flat surfaces of the seat body.

12. A steam trap as claimed in claim 6, wherein said notch is constituted as a recess in said slide valve, said recess extending between said vent outlet and said housing outlet at temperatures below 100 C.

13. A steam trap as claimed in claim 11 comprising a stop lever connected to said seat body and extending in spaced relation from said step to limit displacement of the free end of the other of said arms.

14. A steam trap as claimed in claim 13 comprising a bush supported on said slide valve between said step and said stop lever, said free end of said other arm being threaded'on said bush to adjust the position of said end between said step and said stop lever. 

1. A steam trap comprising a housing having an inlet and an outlet and a trap chamber for condensate, a slidable and rotatable slide valve supported in said housing to control opening of the outlet, a float in said chamber, lever means secured to said float and coupled to said slide valve for rotating the latter in accordance with the level of condensate in said chamber, to open and close said outlet, said lever means including two arms, at least one of which is bimetallic and undergoes deformation, with temperature change, to slidably displace the slide valve, said slide valve having a notch and said housing having a vent outlet respectively positioned such that at low temperatures the notch in the slide valve provides communication between the vent outlet and the outlet of the housing, whereas at high temperature the slide valve is displaced and the vent outlet and housing outlet are disconnected.
 2. A steam trap as claimed in claim 1, wherein said lever means comprises a U-shaped lever inclusive of said arms.
 3. A steam trap as claimed in claim 2 comprising a seat body for said valve, the other of said arms having an end received in a slot provided in said body, said one arm having an end secured to said valve and freely movable laterally.
 4. A steam trap as claimed in claim 3, wherein said valve has an end of reduced diameter engaged in a hole provided in said end which is received in the slot, the valve having an opposite end with at least one flat surface therein, the laterally freely movable end having an opening corresponding in shape to the end of the valve with the flat surface to encircle such end and provide a rotatable connection between said lever means and said valve.
 5. A steam trap as claimed in claim 4, wherein said ends form shoulders on said valve, the distance between the shoulders being such that at temperatures of 100* C. the two ends of the arms are pressed against the shoulders.
 6. A steam trap as claimed in claim 1, wherein said float has a spherical shape, said arms having first ends secured to said float adjacent the center thereof and second remote free ends extending parallel to one another and engaging the slide valve, said arms each including a first portion extending from said first ends and facing said float, said first portions of said arms being curved and having a curvature substantially corresponding to that of said float, said arms each including a second portion connecting said free ends and said first portion, said second portion being curved and having a lesser curvature than said first curvature to smoothly blend therewith and with said free ends.
 7. A steam trap as claimed in claim 6, wherein said first portion of each said arm has a radius of curvature substantially equal to the radius of said float, said first ends being slightly offset from the center of the float so that normally the first portion is spaced from the float, the first portion of the bimetallic arm having a more expansive layer on the outer surface thereof such that at a temperature of about 100* C. the first portion of the latter arm is deformed and contacts the float along the surface thereof.
 8. A steam trap as claimed in claim 7, wherein both arms are bimetallic.
 9. A steam trap as claimed in claim 6, wherein said slide valve includes a flat end portion extending axially of said arms, said one arm having a longitudinal slot receiving said end portion, said slide valve having a convex shoulder in abutment with said first arm, and means secured to said slide valve to hold the first arm in abutment with said convex shoulder.
 10. A steam trap as claimed in claim 9, wherein said shoulder is curved in a horizontal plane and said means for holding the first arm in abutment with the shoulder comprises a vertical pin in said pin engaging the first arm on the side thereof opposite the side in abutment with the convex shoulder.
 11. A steam trap as claimed in claim 9 comprising a seat body for said slide valve, said seat body having opposite flat surfaces from which the ends of the valve protrude, said slide valve having a step at the end thereof remote from the flat end portion, said step forming a shoulder which is spaced from the convex shoulder a distance which is slightly greater than the distance between the flat surfaces of the seat body.
 12. A steam trap as claimed in claim 6, wherein said notch is constituted as a recess in said slide valve, said recess extending between said vent outlet and said housing outlet at temperatures below 100* C.
 13. A steam trap as claimed in claim 11 comprising a stop lever connected to said seat body and extending in spaced relation from said step to limit displacement of the free end of the other of said arms.
 14. A steam trap as claimed in claim 13 comprising a bush supported on said slide valve betWeen said step and said stop lever, said free end of said other arm being threaded on said bush to adjust the position of said end between said step and said stop lever. 